SALT LAKE CITY — The crew operating a flight out of Salt Lake City, forced to land prematurely after encountering turbulence, injuring multiple people, had discussed possible severe conditions along the route before departing, a preliminary report showed.
The report released Tuesday by the National Transportation Safety Board showed what occurred on Delta Flight 56, which had departed Utah on July 30 to Amsterdam, only to land in Minneapolis because of the turbulence.
Twenty-four passengers were injured during the flight, along with 7 crew members.
The report claims the flight crew had discussed possible weather conditions ahead of departing Salt Lake City International Airport at 5:23 p.m. After a smooth departure, the crew "noted that the turbulence predicted on their electronic flight bag weather application was 'in the green' and they had observed only light cirrus clouds," according to the report.
'Felt like a rollercoaster;' passengers describe frightening flight forced to divert:
Following the early indications, the captain turned off the seatbelt sign.
Noticing "weather buildups," the crew requested a flight deviation from air traffic control (ATC), which advised the flight to turn left.
After making the turn, the flight experienced an "overspeed event, which is when a plane exceeds its maximum operating speed by about 15-20 knots. The plane then descended "rapidly," with a "climb/descent cycle repeated about three times over a two- to three-minute period."
"During this time, the vertical acceleration oscillated, reaching a maximum positive peak of about 1.75 g and a minimum negative peak of about -0.5 g. The pitch angle also oscillated, ranging from a low of about 5° nose down to a high of about 10° nose up. Roll angle variations included a maximum of about 40° left wing down and about 5° right wing down," the report explained.
Following the mid-air incident, the crew declared an emergency with ATC and elected to divert the flight to Minneapolis to avoid the weather.
A passenger who was a physician assistant helped the cabin crew with triage on fellow passengers. Of the 24 passengers who were injured, 18 were transported to the hospital, while two of the crew suffered serious injuries.
The release of the full NTSB report on Delta Flight 56 is expected next year.
